Celestron X-Cel LX 9mm v Baader 9mm Ortho

[johninderby]

Celestron X-Cel LX 9mm v Baader 9mm Ortho

I have been very impressed with the new Celestron X-Cell LX eyepieces and thought it would be an interesting exercise to compare my 9mm X-Cel LX to a 9mm BGO. The eyepieces sell for very similar prices. I compared them in white light solar, Ha solar and regular night-time observing.

For white light solar I compared them using a Baader Herschel wedge and an 80mm f/7 APO and a 102mm f/11 achro refractor. Leaving out the obvious difference in the FOV of the eyepieces both eyepieces delivered the same level of surface detail. After swapping eyepieces back and forth quite a few times I just couldn't make up my mind as to which was better. Have to call that one a draw.

For Ha solar I used my 102mm f/11 PST modded scope and again swapped the eyepieces back and forth a number of times. Result was the same as in the white light solar comparison with it being a draw again for detail seen.

Then on to some night time observing using the 80mm f/7 APO. It was fairly cloudy but Jupiter fortunately wasn't obscured and seeing was excellent. I had expected the BGO to have a small advantage, but the level of detail observable on Jupiter and the contrast was a tie. There really was nothing to choose between them. The Pleides showed through another gap in the clouds, and while a 9mm eyepiece isn't the best choice for this, it's still worth looking at. The view through the LX was very pleasing though with very bright pin-point stars, a beautiful sight. The BGO was disappointing in comparison. Not just because of the smaller FOV, but because it gave a noticeably dimmer view. I checked for distortion by letting stars drift across the FOV of both eyepieces. The BGO was sharp from edge to edge. The LX was also very sharp as well with very little edge distortion, and was just as good as the BGO over the same FOV. One curious thing though in comparing these eyepieces was that the LX seemed to be easier to focus than the BGO. There was a little more "snap" to it.

While I haven't tried the 9mm X-Cel LX in faster scopes yet, I have tested the 7mm LX in an 80mm f/4.3 and performance held up very well so I'd expect the 9mm to be just as good. So there you are, a brief comparison, and while there's more testing to do in other scopes and in other seeing conditions the 9mm X-Cel LX is proving to be quite an impressive performer.

John

[Moonshane]

very impressive John.

I like the BGOs but the Celestrons seem to be winning favour with a few people.

[John]

Thats a very interesting report John - thanks

These X-Cel LS's seem to really be making a mark - £69 sounds a bargain for optical performance of this calibre, 16mm of eye relief and a 60 degree FoV - can't go wrong

[johninderby]

Thats a very interesting report John - thanks

These X-Cel LS's seem to really be making a mark - £69 sounds a bargain for optical performance of this calibre, 16mm of eye relief and a 60 degree FoV - can't go wrong

Yes these X-Cel LXs are remarkably good mid-range eyepieces, but at less than mid-range prices. I'd love to do a head to head comparison between them and a Televue Radian.

John

[MjrTom]

Very interesting review John especially regarding light transmission.

I would never have guessed that the BGO would come out worse with it's simpler design.

Live and learn

[Damo636]

H,mmm, very interesting result John. I have been waiting for a 5mm Radian to pop up to replace my 5mm BGO but i might give one of these a go. Great value for that sort of performance.

[Mark at Beaufort]

Thank you John for an interesting review of the two EPs.

I really like the 18mm Celestron X-Cel and use it in my PST and my Stellarvue 80mm finder which is f3.75. The views are sharp in the PST but the edge definition on the finderscope starts to go but with a 4 degree FOV why am I complaining.

As previously stated it has good eye relief and a nice FOV.

I think it is a very good buy for the money.

Yes John it would be good to compare a Radian and the X-Cel in a fast scope.

Mark

[andrew63]

It's always good for some field reviews when new lens appear. These x-cel sound pretty good. I too was surprised by light throughput/contrast which is normally a great strength of the ortho. design.

I compared a 8 bst - similar design to the x-cel - with a 9 vintage orth. in looking at the moon - there was slightly more 'punch' but the bst was very good.

For the last few weeks i've have been using my 6 vixen ortho which i don't like using and comparing my meade 4000 6.7mm UWA - while within the difficulties of observing with the ortho - again the comparison is close with the vixen just a bit more punch again, but matched fairly closely.

The natural conclusion is the very slight advantage is negated by all the other observing advantages offered by these other designs. If i were a lunar or planetary hard core observer though i think i would probably still favour a good ortho.

andrew

[johninderby]

Yes the light transmission has surprised me. I didn't mention in my report that while doing the white light solar observing I used a polarising filter to dim the image for better contrast. After switching from the BGO to the LX the image was brighter and I had to adjust the polarising filter to darken the image to get the best contrast. Thinking about it perhaps the LXs are using newer more advanced coatings.

Pity the clouds prevented any lunar observing last night, but maybe tonight.

John

[spaceboy]

Dibs on the BGO if your selling

[nicnac]

The plan (always subject to change, im married) is to purchase the 7mm or the 9mm next month, will be giving it the works with the TAL (f5)

Will update as and when (with the approval of the wiff that is)